Administering an injection is a process which presents a number of risks and challenges for users and healthcare professionals, both mental and physical. Injection devices typically fall into two categories—manual devices and autoinjectors. In a conventional manual device, manual force is required to drive a medicament through a needle. This is typically done by some form of button/plunger that has to be continuously pressed during the injection. There are numerous disadvantages associated with this approach. For example, if the button/plunger is released prematurely, the injection will stop and may not deliver an intended dose. Further, the force required to push the button/plunger may be too high (e.g., if the user is elderly or a child). And, aligning the injection device, administering the injection and keeping the injection device still during the injection may require dexterity which some patients (e.g., elderly patients, children, arthritic patients, etc.) may not have.
Autoinjector devices aim to make self-injection easier for patients. A conventional autoinjector may provide the force for administering the injection by a spring, and trigger button or other mechanism may be used to activate the injection. Autoinjectors may be single-use or reusable devices.
Conventional delivery devices may also have limited feedback mechanisms. For example, some conventional delivery devices may only provide an audible feedback when an injection is complete. Thus, a patient may be startled when he/she feels a needle insertion or pressure associated with injection of a medicament if there is no warning. In this case, the patient may move or react during needle insertion or medicament delivery which may lead to injury, pain, or incorrect dose delivery.
Thus, there remains a need for an improved medicament delivery device with a medicament delivery initiation indicator.